Craig J. Eagle

Effect of Celecoxib on Cardiovascular Events and Blood Pressure in Two Trials for the Prevention of Colorectal Adenomas

Background— Cyclooxygenase-2 (COX-2) inhibitors have been shown to reduce colorectal adenomas but have been associated with increased cardiovascular risk. Methods and Results— The Adenoma Prevention With Celecoxib (APC) trial studied celecoxib 200 mg twice daily and 400 mg twice daily and the Prevention of Spontaneous Adenomatous Polyps (PreSAP) trial used 400 mg once daily to test the efficacy and safety of celecoxib against placebo in reducing colorectal adenoma recurrence after polypectomy. An independent safety committee for both studies adjudicated and categorized serious cardiovascular events and then combined individual patient data from these long-term trials to improve the estimate of the cardiovascular risk and blood pressure changes associated with celecoxib compared with placebo. For adjudicated cardiovascular events, 77% and 54% in APC and PreSAP, respectively, had 37 months of follow-up. For APC and PreSAP combined, 83 patients experienced cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or heart failure. The hazard ratio for this prespecified composite end point was 2.6 (95% confidence interval [CI], 1.1 to 6.1) in patients taking 200 mg twice daily, 3.4 (95% CI, 1.5 to 7.9) in patients taking 400 mg twice daily in APC, and 1.3 (95% CI, 0.6 to 2.6) in patients taking 400 mg once daily in PreSAP (P for heterogeneity=0.13 comparing the combined doses in APC with the dose in PreSAP). The overall hazard ratio for this composite end point was 1.9 (95% CI, 1.1 to 3.1). Both dose groups in APC showed significant systolic blood pressure elevations at 1 and 3 years (200 mg twice daily: 1 year, 2.0 mm Hg; 3 years, 2.6 mm Hg; 400 mg twice daily: 1 year, 2.9 mm Hg; 3 years, 5.2 mm Hg); however, the 400 mg once daily group in PreSAP did not (P<0.0001 between studies). Conclusions— Celecoxib at 200 or 400 mg twice daily or 400 mg once daily showed a nearly 2-fold–increased cardiovascular risk. The trend for a dose-related increase in cardiovascular events and blood pressure raises the possibility that lower doses or other dose intervals may be associated with less cardiovascular risk.

Five-Year Efficacy and Safety Analysis of the Adenoma Prevention with Celecoxib Trial

The Adenoma Prevention with Celecoxib Trial examined the efficacy and safety of the cyclooxygenase (Cox)-2 inhibitor, celecoxib, for sporadic colorectal adenoma prevention in patients at high risk for colorectal cancer. The trial randomized 2,035 subjects to receive either placebo, celecoxib 200 mg twice daily, or celecoxib 400 mg twice daily. The primary study safety and efficacy analyses involved 3 years of treatment. The results showed significant antitumor effect but also indicated increased cardiovascular adverse events in patients treated with celecoxib compared with placebo. A total of 933 patients participated in an extension of the Adenoma Prevention with Celecoxib Trial, with a planned total treatment and surveillance duration of 5 years. Study medication was stopped early, resulting in a median treatment duration of 3.1 years for those with a year 5 colonoscopy. Patients treated on the placebo arm had a cumulative adenoma incidence of 68.4% over 5 years of observation. This figure was 59.0% (P < 0.0001) for those receiving low-dose celecoxib, and 60.1% (P < 0.0001) for those receiving high-dose celecoxib. The cumulative incidence of advanced adenomas over 5 years was 21.3% of those taking placebo, 12.5% (P < 0.0001) of those taking low dose celecoxib and 15.8% (P < 0.0001) of those taking high-dose celecoxib. Investigator reported treatment emergent adverse events were similar across all treatment groups for categories including renal and hypertensive events and gastrointestinal ulceration and hemorrhage events. For a category composed of cardiovascular and thrombotic events, the risk relative to placebo was 1.6 (95% confidence interval, 1.0, 2.5) for those using 200 mg twice daily celecoxib and 1.9 (95% confidence interval, 1.2, 3.1) for those using 400 mg twice daily celecoxib. Secondary analysis showed an interaction between a baseline history of atherosclerotic heart disease and study drug use with respect to cardiovascular and thrombotic adverse events (P = 0.004). These results confirm the inhibitory effect of celecoxib on colorectal adenoma formation, and provide additional safety data indicating an elevated risk for cardiovascular and thrombotic adverse events, particularly for patients with preexisting atherosclerotic heart disease.

Aberrant crypt foci in the Adenoma Prevention with Celecoxib trial

Abstract Aberrant crypt foci (ACF) are the earliest visible neoplastic lesions in the colorectum. The natural history of these lesions and their role in the adenoma-carcinoma sequence are unknown. We studied ACF in a subset of patients randomized to placebo (n = 17), celecoxib (200 mg twice daily; n = 15), or celecoxib (400 mg twice daily; n = 13) in the Adenoma Prevention with Celecoxib (APC) trial. Magnification chromoendoscopy was done to identify, count, and biopsy ACF within the rectum at baseline and after 8 to 12 months of treatment. A total of 655 ACF were identified in 45 patients. We examined 70 of these ACF histologically, and all 70 were nondysplastic. Cohort characteristics and APC trial treatment results for substudy patients were similar to those of the overall APC trial. There was no significant modulation of ACF by celecoxib (versus placebo; P = 0.77). Immunohistochemical comparison of ACF with adjacent normal mucosa showed that ACF had an increased proliferative index as determined by Ki-67 (P < 0.0001), but lacked other features of neoplasia such as increased cyclooxygenase-2 expression and microvessel density, nuclear localization of β-catenin, or decreased expression of the tumor suppressors SMAD4, Estrogen Receptor α, or MGMT. Only baseline SMAD4 expression in ACF correlated with posttreatment adenoma recurrence (independent of treatment arm; P = 0.01). The presence or number of nondysplastic ACF did not correlate with a higher risk of synchronous advanced or recurrent adenomas. Our overall results indicated that nondysplastic ACF were not accurate surrogate endpoint biomarkers of recurrent colorectal adenomas in the APC trial.

The Safety and Efficacy of Celecoxib in Children With Familial Adenomatous Polyposis

OBJECTIVES:Celecoxib is approved as an adjunctive chemopreventive agent in adults with familial adenomatous polyposis (FAP). Its safety and efficacy for colorectal polyps in children is unknown. We evaluated the short-term (3 months) safety and preliminary efficacy of celecoxib in children with FAP.METHODS:This was a phase I, dose-escalation trial, with three successive cohorts of six children. Children of ages 10–14 years with APC gene mutations and/or adenomas with a family history of FAP were studied at M.D. Anderson Cancer Center and the Cleveland Clinic. Colonoscopy was performed at baseline and month 3. Random assignment was in a 2:1 generic:placebo ratio, escalating from cohort 1 (4 mg/kg/day) to cohort 2 (8 mg/kg/day) to cohort 3 (16 mg/kg/day). Adherence and adverse event (AE) monitoring was conducted at 2-week intervals during drug administration. Safety profile, difference in number, and percent change in colorectal polyps were compared among the four treatments (placebo and the three dose-escalation groups).RESULTS:Eighteen subjects completed drug dosing and both colonoscopies. Median age was 12.3 years (56% female). No clinically meaningful differences in AEs were seen between placebo subjects and subjects at any of the three celecoxib doses. Median polyp count at baseline was 31. There was a 39.1% increase in the number of polyps in placebo subjects at month 3, whereas in the highest dose celecoxib group, 16 mg/kg/day, a 44.2% reduction was seen (P=0.01).CONCLUSIONS:Celecoxib at a dose of 16 mg/kg/day, corresponding to the adult dose of 400 mg BID, is safe, well tolerated, and significantly reduced the number of colorectal polyps in children with FAP.

Cytochrome P450 2C9 Variants Influence Response to Celecoxib for Prevention of Colorectal Adenoma

BACKGROUND & AIMS Variants in the cytochrome P450 2C9 (CYP2C9) gene are associated with impaired metabolism of celecoxib. We examined the influence of CYP2C9*2 (R144C) and CYP2C9*3 (I359L) variants on dose-related response or toxicity in a randomized trial of celecoxib. METHODS We identified individuals with CYP2C9*2 and CYP2C9*3 genotypes (>or=1 variant allele) in the Adenoma Prevention with Celecoxib trial. Following adenoma removal, patients were assigned randomly to groups given placebo or low-dose (200 mg twice daily) or high-dose (400 mg twice daily) celecoxib and underwent follow-up colonoscopies at 1 and/or 3 years. RESULTS Among 1660 patients, 21% were CYP2C9*2, and 12% were CYP2C9*3 genotypes. Overall, celecoxib was associated with a dose-dependent reduction in adenoma, compared with placebo, with relative risks (RR) of 0.65 (95% confidence interval [CI]: 0.56-0.76) for the low-dose and 0.54 (95% CI: 0.46-0.63) for the high-dose groups. However, the additional protective effect of the high dose, compared with the low-dose, was observed only in those with CYP2C9*3 genotypes (RR, 0.51; 95% CI: 0.30-0.87). The high dose, compared with low dose, was not associated with significant risk reduction among those with CYP2C9*2 (RR, 0.83; 95% CI: 0.57-1.21) or wild-type (RR, 0.89; 95% CI: 0.72-1.11) genotypes. Compared with placebo, a higher incidence of cardiovascular events was associated with both doses among patients with wild-type genotypes but only with the high dose among patients with variant genotypes. CONCLUSIONS The greater efficacy of high-dose celecoxib, compared with the low-dose, in preventing colorectal adenoma appears confined to individuals with slow metabolizer (CYP2C9*3) genotypes. Genetic variability influences susceptibility to the potential benefits and hazards of celecoxib.

A randomized controlled trial of celecoxib to prevent recurrence of nonmuscle-invasive bladder cancer

Significant morbidity and expense result from frequent recurrences of nonmuscle-invasive bladder cancer (NMIBC) after standard treatment, and carcinoma in situ (Tis) is a poor prognostic factor. Predicated on observational and preclinical data strongly supporting cyclooxygenase-2 (COX-2) in the pathogenesis, and the activity of COX-2 inhibitors, in bladder cancer, we conducted a randomized, double-blind, placebo-controlled trial to determine whether celecoxib could reduce the time-to-recurrence (TTR) in NMIBC patients at high risk for recurrence. A total of 146 patients were randomized to celecoxib (200 mg) or placebo orally twice daily for at least 12 months. The average treatment duration was 1.25 years. Primary intent-to-treat analysis revealed celecoxib did not statistically significantly prolong TTR compared with placebo (P = 0.17, log rank) with a median follow-up of 2.49 years. The recurrence-free rate at 12 months with celecoxib was 88% (95% CI: 0.81–0.96) versus 78% (95% CI: 0.69–0.89) with placebo. After controlling for covariates with Cox regression analysis, recurrence rates did not differ between the two study arms (HR = 0.69; 95% CI: 0.37–1.29). However, celecoxib had a marginally significant effect on reducing metachronous recurrences (vs. placebo) with HR of 0.56 (95% CI: 0.3–1.06; P = 0.075). Celecoxib was well tolerated, with similar adverse events and quality-of-life in both arms. Our clinical trial results do not show a clinical benefit for celecoxib in preventing NMIBC recurrence but further investigation of COX-2 inhibitors in this setting is warranted. Cancer Prev Res; 4(10); 1580–9. ©2011 AACR.

Statin Use and Colorectal Adenoma Risk: Results from the Adenoma Prevention with Celecoxib Trial

Statins are widely prescribed for cardiovascular disease prevention and also commonly used in patients at high risk for colorectal cancer. We report the results of a planned secondary analysis of the relationship between statin use and colorectal adenoma risk in a large chemoprevention trial. The Adenoma Prevention with Celecoxib (APC) trial randomized 2,035 adenoma patients to receive placebo (679 patients), 200 mg celecoxib twice daily (bid; 685 patients), or 400 mg celecoxib bid (671 patients). The study collected complete medical history and medication use data and performed colonoscopic surveillance to 5 years after study enrollment. The effects of statin use on newly detected adenomas and cardiovascular adverse events were analyzed as time-dependent variables by multivariable Cox regression. Statins were used by 36% (n = 730) of APC trial participants. When adjusted for covariates including cardioprotective aspirin use, age, and sex, participants on the placebo arm who used statins at any time had no benefit over 5 years compared with never users (risk ratio, 1.24; 95% confidence interval, 0.99-1.56; P = 0.065). Statin use for >3 years increased adenoma risk over 5 years (risk ratio, 1.39; 95% confidence interval, 1.04-1.86; P = 0.024). For all comparisons of patients treated with celecoxib, adenoma detection rates for statin users and nonusers were equivalent. Consistent with their use in patients at high risk, cardiovascular serious adverse events were more common among statin users. For patients at high risk of colorectal cancer, statins do not protect against colorectal neoplasms and may even increase the risk of developing colorectal adenomas. Cancer Prev Res; 3(5); 588–96. ©2010 AACR.

The APC and PreSAP Trials: A Post Hoc Noninferiority Analysis Using a Comprehensive New Measure for Gastrointestinal Tract Injury in 2 Randomized, Double-Blind Studies Comparing Celecoxib and Placebo

BACKGROUND Previous gastrointestinal (GI) outcomes of nonsteroidal anti-inflammatory drug (NSAID) trials have focused on upper GI events, although recent evidence suggests NSAID-related lower GI effects are important and clinically relevant. OBJECTIVE We assessed the long-term GI adverse event (AE) profile of celecoxib in a nonarthritis population. The aim of this post hoc analysis was to determine the incidence of serious GI AEs, using a new Clinically Significant Upper and/or Lower GI Events end point. METHODS Patients from 2 colorectal adenoma recurrence studies were included. Patients received celecoxib 200 mg/400 mg BID, 400 mg once daily, or placebo over 3 years. The analysis measured noninferiority, using a prespecified definition of noninferiority. Celecoxib was predefined to be noninferior to placebo if the upper limit of the 95% CI for the hazard ratio (HR) with celecoxib was <1.25, at any dose, compared with the placebo (calculated using the Cox proportional hazards model). RESULTS A total of 3588 patients were included; in the primary analysis, the HR for celecoxib (any dose) compared with placebo was 1.22 (95% CI: 0.69-2.18; P = 0.4948). In the secondary dose analyses, the HR associated with a 400-mg daily dose, compared with placebo, was 1.04 (95% CI: 0.55-1.96; P = 0.9149); for 800 mg/d, the HR was 1.79 (95% CI: 0.82-3.89; P = 0.1427). In a third covariate analysis, low-dose aspirin use (HR = 2.33; 95% CI: 1.33-4.08) and age ≥65 years (HR = 1.82; 95% CI, 1.05-3.15) was suggested to have a statistically significant association with increased risk of GI AEs. Study limitations include retrospective evaluation and small sample size of patients with GI AEs. CONCLUSIONS The noninferiority of celecoxib to placebo was not established because the HR for the time to the first Clinically Significant Upper and/or Lower GI Event was greater than the prespecified upper limit of 95% CI for noninferiority. In addition, HRs associated with daily doses of 400 or 800 mg celecoxib compared with placebo were not significant. However, a significantly increased risk of clinically significant upper and/or lower GI events was observed in low-dose aspirin users (≤162.5 mg average daily use) and in patients ≥65 years of age.

Abstract LB-173: Statin use and colorectal adenoma risk: Results from the Adenoma Prevention with Celecoxib (APC) trial

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Discussant: John A. Baron, Dartmouth Medical School, Lebanon, NH. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-173.

Response to Letter Regarding Article, “Effect of Celecoxib on Cardiovascular Events and Blood Pressure in Two Trials for the Prevention of Colorectal Adenomas”

We thank Dr Cen for his thoughtful comments about our work.1,2 He suggests combining covariates from the Adenoma Prevention With Celecoxib (APC) and Prevention of Colorectal Sporadic Adenomatous Polyps (PreSAP) trials into a single Cox model and using the resulting hazard ratio to estimate the overall effect of celecoxib on cardiovascular end points. This approach treats the variable trial (APC or PreSAP) as 1 ingredient in a stew. We believe in maintaining the integrity of the ingredients as long as possible to allow the flavor of each trial to retain its unique contribution. …